首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5285篇
  免费   443篇
  国内免费   10篇
耳鼻咽喉   52篇
儿科学   143篇
妇产科学   99篇
基础医学   680篇
口腔科学   109篇
临床医学   494篇
内科学   1096篇
皮肤病学   111篇
神经病学   515篇
特种医学   171篇
外国民族医学   6篇
外科学   831篇
综合类   123篇
一般理论   8篇
预防医学   450篇
眼科学   206篇
药学   313篇
中国医学   16篇
肿瘤学   315篇
  2022年   33篇
  2021年   92篇
  2020年   44篇
  2019年   80篇
  2018年   97篇
  2017年   68篇
  2016年   64篇
  2015年   76篇
  2014年   120篇
  2013年   217篇
  2012年   273篇
  2011年   297篇
  2010年   170篇
  2009年   155篇
  2008年   259篇
  2007年   287篇
  2006年   280篇
  2005年   293篇
  2004年   297篇
  2003年   287篇
  2002年   269篇
  2001年   55篇
  2000年   59篇
  1999年   66篇
  1998年   62篇
  1997年   43篇
  1996年   46篇
  1995年   54篇
  1994年   54篇
  1993年   65篇
  1992年   48篇
  1991年   33篇
  1990年   42篇
  1989年   37篇
  1988年   30篇
  1987年   38篇
  1986年   36篇
  1985年   43篇
  1984年   57篇
  1983年   49篇
  1982年   47篇
  1981年   63篇
  1980年   54篇
  1979年   47篇
  1978年   48篇
  1977年   49篇
  1976年   35篇
  1975年   34篇
  1974年   42篇
  1973年   39篇
排序方式: 共有5738条查询结果,搜索用时 218 毫秒
1.
2.
3.
Sera from 43 leprosy patients were tested for antibodies that bound to normal human nerve. Thirty-eight percent showed positive staining as demonstrated by indirect immunofluorescence. Only 1 out of 30 control sera tested displayed similar staining. Western blots of myelin and neural intermediate filament (IF) proteins were tested with patient sera. Two of the anti-neural antibody (ANeAb)-positive leprosy sera bound to the P0 protein of PNS myelin. All 17 ANeAb-positive leprosy sera displayed 2 or more bands in the molecular weight range of Mr 45 000-55 000, when tested against IF proteins. One explanation for these findings is that leprosy patients produce antibodies to intermediate filament (IF) proteins released subsequent to the bacterial invasion of the peripheral nerves. The importance of these autoantibodies in the pathogenesis of leprosy is discussed.  相似文献   
4.
OBJECTIVE: Alcohol might increase calcitonin but this assertion is mainly based on the acute effect of the drug in small animals and humans. The aim of this study was to investigate the effect of chronic alcoholic intoxication on plasma calcitonin (CT) levels. DESIGN: 20 smoking male subjects admitted to be weaned from chronic daily alcohol consumption >100 g were included after informed consent. Blood was sampled upon admission (T0) and after 5 (T5) and 21 (T21) days of alcohol weaning to measure mean erythrocyte volume, gamma-glutamyltransferase (GGT), calcium, gastrin, and CT levels. The control group consisted of 30 male subjects with daily alcohol consumption <20 g. MAIN OUTCOME: The characteristics of the alcohol group were as follows (mean +/- SD): age 41.2 +/- 13 years old; mean erythrocyte volume: 96.0 +/- 4.2 microm(3) (N: 85-95); calcium level: 94.7 +/- 3.7 mg/L (N: 85-105); gastrinemia: 59.3 +/- 14.9 ng/mL (N: <120). At T0 and T21, three alcoholic subjects had CT levels above 10 pg/mL, usually considered as the normal cut-off value. There was no correlation between CT and the different biochemical parameters at T0, T5, and T21. There was no difference between CT levels at the different stages in the alcohol group (T0: 6.4 +/- 3.6 pg/mL; T5: 6.5 +/- 5.3 pg/mL; T21: 8.4 +/- 5.6), although GGT significantly decreased with weaning duration (T0: 248 +/- 354 IU/L; T5: 211 +/- 290 IU/L; T21: 79 +/- 90 IU/L; ANOVA, p <0.05). But a significant difference was found between mean CT levels in the alcohol group and in the control group (3.1 +/- 0.7 pg/mL, p <0.0001). CONCLUSIONS: This study suggests that mean CT levels of chronically alcoholic smoking male subjects are higher than those of an age- and sex-matched control group. However, most alcoholic patients exhibited CT levels <10 pg/mL. No decrease in CT levels was noted over a short period of alcohol weaning. As CT measurement is currently recommended in thyroid nodule assessment, this finding may be important to know how to decipher borderline values of CT.  相似文献   
5.
6.
7.
Laparoscopic hysterectomy   总被引:1,自引:0,他引:1  
Summary Thirty-three patients were selected for laparoscopic hysterectomy and operated on in the Department of Obstetrics, Gynecology and Reproductive Medicine of Clermont-Ferrand University Hospital. Surgical techniques included blunt dissection with scissors and bipolar coagulation to achieve hemostasis. A case was considered successful when all the uterine vessels were treated by laparoscopy. Twenty-four cases were completed laparoscopically (72.7%). None of these patients had postoperative bleeding; 22 had an uneventful postoperative recovery. Nine procedures were converted to laparotomy (27.3%), five because of a difficult or unsatisfactory hemostasis. We conclude that in selected cases, a total hysterectomy can be performed safely by experienced laparoscopists. Further technological progress is necessary to make this procedure more acceptable. Its value as compared to the others will have to be demonstrated.  相似文献   
8.
The cascade of physiologic mechanisms in response to infection, the acute-phase response, is recognized as playing a major role in host defence. One such response is the hypoferremia that is consistently reported to occur during bacterial infection. This study aimed to determine whether the alterations in plasma iron were conditionable using the conditioned taste aversion (CTA) paradigm. The regime involved the pairing of a novel-tasting saccharin solution with bacterial endotoxin. Seven days after the initial pairing of these stimuli (the test day), the saccharin solution was represented. Animals exposed to this condition displayed a significant reduction in the level of plasma iron. Animals treated with an intraperitoneal dose of 400 μg/Kg lipopolysaccharide (LPS) displayed lower conditioned iron levels than rats infused with 100 μg/Kg LPS; however, this difference was not significant. These results showed that in addition to other acute-phase responses (fever and anorexia), plasma iron alterations are able to be manipulated through behavioral manipulations.  相似文献   
9.
The goal of the present study was to identify cytochemical markers characteristic of muscle afferents in hatchling chicks. To this end, we stained neurons in the trigeminal mesencephalic nucleus with a variety of markers that label subsets of neurons in avian dorsal root ganglia. We found that trigeminal mesencephalic neurons are surprisingly heterogeneous in their cytochemical make-up, expressing, to varying degrees, substance P, cholecystokinin, carbonic anhydrase, calbindin D-28k, parvalbumin, and S-100β. Calbindin D28k and S-100β appeared to be expressed equally in medial and lateral divisions of the trigeminal mesencephalic nucleus. In contrast, substance P- and cholecystokinin-immunoreactive neurons were more abundant in the medial division, whereas carbonic anhydrase activity and parvalbumin immunoreactivity were stronger in the lateral division. We were unable to detect met-enkephalin, neuropeptide Y, calcitonin gene-related peptide, vasoactive intestinal peptide, somatostatin, γ-aminobutyric acid, or tyrosine hydroxylase in the trigeminal mesencephalic nucleus. Moreover, these neurons did not appear to bind the lectin Dolichos biflorus agglutinin. The heterogeneity of expression of markers among trigeminal mesencephalic nucleus neurons, especially between neurons in the medial and lateral divisions, suggests that these neurons are functionally diverse.  相似文献   
10.
Our group has previously reported significant changes in the incorporation of precursors into glycerophospholipids, particularly phosphatidylserine, in polymorphonuclear cells obtained from the peripheral blood of cluster headache patients, when compared with controls. The potential of these results led to further work using both the previous methodology and a modified isolation technique to obtain polymorphonuclear cells in as pure a state as possible. Neither the new results obtained using the original technique, nor the results with high purity polymorphonuclear cells from controls and cluster headache patients, confirm the marked changes in precursor uptake into glycerophospholipids originally reported.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号